/Engine/Source/Runtime/Engine/Classes/Materials/MaterialInstance.h
Initiates caching for this shader resource that will be finished when each material resource IsCompilationFinished returns true.
void BeginCacheShadersForResources ( EShaderPlatform ShaderPlatform, const [TArray](API\Runtime\Core\Containers\TArray)< [FMaterialResource](API\Runtime\Engine\FMaterialResource) * > & ResourcesToCache, EMaterialShaderPrecompileMode PrecompileMode, const [ITargetPlatform](API\Developer\TargetPlatform\Interfaces\ITargetPlatform) * TargetPlatform )